The Lipoxygenase Gene Family in Poplar: Identification, Classification, and Expression in Response to MeJA Treatment

Lipoxygenases (LOXs) are important dioxygenases in cellular organisms. LOXs contribute to plant developmental processes and environmental responses. However, a systematic and comprehensive analysis has not been focused on the LOX gene family in poplar. Therefore, in the present study, we performed a comprehensive analysis of the LOX gene family in poplar.

Using bioinformatics methods, we identified a total of 20 LOX genes. These LOX genes were clustered into two subfamilies. The gene structure and motif composition of each subfamily were relatively conserved. These genes are distributed unevenly across nine chromosomes. The PtLOX gene family appears to have expanded due to high tandem and low segmental duplication events. Microarray analysis showed that a number of PtLOX genes have different expression pattern across disparate tissues and under various stress treatments. Quantitative real-time PCR (qRT-PCR) analysis was further performed to confirm the responses to MeJA treatment of the 20 poplar LOX genes. The results show that the PtLOX genes are regulated by MeJA (Methyl jasmonate) treatment.

This study provides a systematic analysis of LOX genes in poplar. The gene family analysis reported here will be useful for conducting future functional genomics studies to uncover the roles of LOX genes in poplar growth and development.